1. Field of the Invention
The present invention relates to optical elements having a cured hard coating film wherein the coating film is excellent in hot water resistance, and light-resistance and weathering resistance are not impaired even when an antireflection film made by vapor deposition of inorganic oxides is applied on the coating film.
2. Description of the Related Art
It is well known to form a cured hard coating film containing an organosilicon polymer on the surface of synthetic resin of high refractive index such as polyurethane resin and halogen-containing resin so as to improve scuff or mar resistance of the resin. It is also known to contain a particulate metal oxide of high refractive index in a hard coating film so as to inhibit formation of interference fringes on the synthetic resin of high refractive index having tile hard coating film. For example, Japanese Patent Disclosure No. 172369/1991 discloses coating compositions containing an organosilicon compound and fine particles of stannous oxide coated with fine particles of tungstic oxide, and optical elements having a hard coating film formed therefrom.
The optical elements having hard coating film disclosed in Japanese Patent Disclosure No. 172369/1991, however, had the problem that light-resistance and weathering resistance are lowered when an antireflection film consisting of inorganic oxide vapor-deposited film is applied on the hard coating film on an optical base material. Therefore, the optical elements having the antireflection material are not preferable in appearance for lenses of glasses, since they tend to yellow easily with the passage of time.
The present invention has been made for eliminating said problems of the prior art, and it is intended to provide an optical element by the use of a coating composition wherein light-resistance and weathering resistance of the cured coating film formed with the coating composition are not lowered when the inorganic oxide vapor-deposited film is applied thereon.